One of Danny Williams' first signings, Butler was captured from Newcastle United for £5,500 in August 1965. Originally a right back, Butler struggled to fit in at Swindon, until an inspired move from Williams moved him into a midfield position.

A committed performer who always gave 100%, Butler remained a regular member of the Town side for nine years, having made over 350 league appearances for the club, in one of the most successful periods in the club's history. He was an integral part of the team that won the League Cup and promotion to Division Two in 1968/1969.

He left the club in August 1976, joining Aldershot on a free transfer.